The original CE2 clearomizers had thin plastic tubes that cracked, often coming cracked out of the box. They also had a very small area on the base for the tube to fit on to which lead to leaks. These are the ones to avoid like the plague and they are often the ones you can find being sold at a 'great' price.
For a while a few places offered improved versions of these with a thicker clear plastic tube that 'resisted' cracking. These still had the ridiculously small area on the base for the tube to fit on to so still suffered from leaking and the tube could get detached from the base at the slightest knock. Better, more usuable, but still flawed. It is these second ones that most clearo aficionados would modify using the plastic tube from 3ml BD syringes. These tubes still suffered from being easily knocked off but are otherwise fine and never crack or break. The clearo became usable!
There is now a much improved version on sale. At last this one has a much increased area of base for the tube to locate on to and has an 'indestructible' plastic tube. These are sold mostly by one vendor, GotVapes, and they are known under a proprietary name of 'Fluxomizers'. They are still CE2's though! One small drawback of the Fluxomizer is the tubing is slightly smaller diameter which means that the silcion rubber seals that fit in the top are much tighter. Various users have different fixes for this. Some remove the seals completely, some only use one seal and flip it upside down etc. Personally I still use the 3ml BD syringe tubes on these bases and I find them just about perfect. The wider bases stop all the leaks from the base even with the larger diameter BD syringe tube and the seals are easy to fit.
So there you are. Don't buy the original two types and you will avoid most of the problems. The ones to try are the Fluxomizers from GotVapes, they are the most recent evolution of the CE2 clearo. My wife and I have five each which we use throughout the week (we swap them when the flavour diminishes after 2-3 days) then I have a mass clean up at the weekend. I remove the seals and tube, rinse them in hot water, dry burn the coils until the wicks are white again and reassemble. We started using these ten Fluxomizers over three months ago and seven are still going strong. I think I have junked three of them along the way for the bottom seal failing causing flooding, the rest are still in use. I don't know of a better or more economical way to vape, with the XL clearo's capacity of 1.8ml they don't need filling very often and they give huge vapour and flavour.
I like 'em
I read so many people having problems with these simply becuase they do not know the tricks which is a big shame because nothing comes clome in my opinion. I keep pondering whether to write an illustrated article on the clearo and how to get the best out of it (we have been using them exclusively now for six months) but I'm not sure if it would be of any use to anyone.